Cabin Air Quality

Outline Statement from the Air Safety Group:

The 'Cranfield Report' - the Aircraft Cabin Air Sampling Study, 2011 - did not exonerate industry - because the study was not able to measure an actual fume event. The UK Government's stance of citing the report as evidence that no risk exists may be considered ill-advised. It is believed a recent KLM study also failed to measure a fume event.

The 'normal' operation of aircraft air conditioning systems seems to indicate low (but 'safe') levels of contamination. However, there has not been enough scientific measurement of 'real-time' fume events to decide whether these events may carry higher concentrations of contaminants and so present an increased risk to those aboard.

There has been widespread reporting of' oily smoke' in the cabin and flight-deck of many aircraft at times. It is entirely reasonable to say that 'fume events' occur on some flights.

There are numerous validated reports of post-fume event incapacitation of crews. Courts in the EU and Australia have found in favour of the crew.

There has been plenty of research into the toxicity of Organo-Phosphates (OP) including the Tri-Cresyl Phosphate (TCP) family of compounds found in aero-engine oils- they are particularly toxic to the central nervous system of humans. Because of this and all of the above, a reasonable person would take more precautions and seek better mitigations than seems to be the industry norm.

There seem to be no reliable means of fully testing blood/urine, especially after delays in getting to a suitable laboratory. Epidemiological studies of aircrew illness may help establish a link.

It appears that a means of continuous air-composition sampling fitted to 'in-service' aircraft is not yet fully developed.

Aircraft with alternative means of cabin air conditioning/pressurization are rare (B787).

There appears to be few viable alternatives to TCP for use in aero-oils.

Because of the enormous seriousness of the neuro-toxological effects, the 'relatively low threat' of OP poisoning of the crew and passengers must be taken more seriously and given greater weight until enough relevant data becomes available about fume events. Failure to do this will ferment the perception that regulatory bodies, airlines and manufacturers are 'turning a blind-eye' to the threat - which will smack of complacency and unprofessional risk management. This will greatly undermine the standing of the safety oversight processes, which is in no-one's best interests.

Ultimately, until such time as there is enough validated evidence to prove or disprove a link between fume events and illnesses in air-travelers and crew-members, the ASG believes the authorities, operators and manufacturers should take all possible and immediate steps to mitigate the risks of OP poisoning aboard civilian registered aircraft. The aircraft manufacturers may even be well-advised to make financial provision for large compensation pay-outs in case the link is ever proven.

The ASG supports a drive by Captain Hoyte and the Aerotoxic Association to collect more data and determine positively whether any physiological or pathological links between fume events and illnesses exist.